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2.1 Earth's Crust in Motion

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Vocabulary

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stress: a force that acts on rock to in the crust to change its shape or volume
earthquake: a shaking movement that results from movement of rock beneath Earth's surface.
shearing: a type of stress that pushes a mass of rock in two opposite directions.
tension: a type of stress force that pulls on crust, stretching rock so it's thinner in the middle.
compression: a force that squeezes rock together until it folds or breaks.
deformation: any change in shape or volume in Earth's crust.
folds: bends in rock that form when compression shortens and thickens a part of Earth's crust.
anticline: an anticline is a fold in rock that bends upward into an arch.
syncline: a syncline is a fold in rock that bends downward into an valley.
plateau: a large area of flat land elevated way above sea level.

Outline

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Intro

Stress in the Crust

Types of Stress

• shearing
  • the stress that pushes mass of rocks into two opposite directions
• tension
  • the stress force that pulls on the crust, stretching rock so that it becomes thinner in the middle
• compression
  • the stress force that squeezes rock until it folds or breaks

Kinds of Faults

• Strike-slip fault
  • two rocks slip past each other in a sideways, up, or down motion.
• Normal fault
  • the fault is at an angle so one block of rock lies above the fault when the other is below the fault.
• Reverse fault
  • same structure as a normal fault, but the blocks move in opposite direction.

Friction Along Faults

Mountain Building

• Mountains formed by faulting
  • fault-block mountain
• Mountains formed by folding
  • Himalayas
  • Alps
• anticlines and synclines
  • anticline
    • The fold in a rock that bends upward into an arch
  • syncline
    • The fold in a rock that bends downward in the middle to form a bowl
• Plateaus
  • Plateaus are large areas of flat land that are elevated way above sea level
  • Now a days, there are lots of the plateaus that are more than 1,500 meter above sea level